Safety trailer hitch

ABSTRACT

A safety trailer hitch in which a yoke is secured to the tow bar of the trailer and to the hitch of the towing vehicle to prevent the trailer from becoming disconnected should the socket portion on the trailer become detached from the ball. The yoke may be easily disconnected from the trailer hitch when disconnecting the trailer from the towing vehicle. In a modified form of the invention a finger on the trailer hitch is arranged to be swung into a position overlying the socket to prevent the socket from detaching from the ball. When disconnecting the trailer the finger is swung out of the way to permit the socket to be lifted off of the ball.

United States Patent Kothmann H July 18, 1972 [54] SAFETY TRAILER HITCH21 Appl. No.: 23,373

2,139,970 12/1938 Moore ..280/491 FOREIGN PATENTS OR APPLICATIONS560,939 4/1957 Italy ..2s0/4 s7 Primary Examiner-Leo FriagliaAttorney-Herman, Davidson and Berman [57] ABSTRACT A safety trailerhitch in which a yoke is secured to the tow bar of the trailer and tothe hitch of the towing vehicle to prevent the trailer from becomingdisconnected should the socket portion on the trailer become detachedfrom the ball. The yoke may be easily disconnected from the trailerhitch when disconnecting the trailer from the towing; vehicle. In amodified form of the invention a finger on the trailer hitch is arrangedto be swung into a position overlying the socket to prevent the socketfrom detaching from the ball. When disconnecting the trailer the fingeris swung out of the way to permit the socket to be lifted off of theball.

5 Clains, 16 Drawing Figures Patented July 18, 1972 3,677,564

4 Sheets-Sheet l BY 5% gi WW ATTOK/VEYIS.

Patented July 18 1972 3,677,564

4 Sheets-Sheet 2 BY M 2 m Patented July 18, 1972 4 Sheets-Sheet 5INVENTOR. 6/4 BERT 0. KO Tf/MA/V/V,

Patented July 18, 1972 3,677,564

4 Sheets-Sheet 4 IXYEYTIJFL G/L BER T 0. KO THM/RA/M A TTOR \FIYS.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to safety trailer hitches of the type normally used totow boat trailers, utility trailers, camping trailers, and the like witha passenger automobile or light truck.

2. Description of the Prior Art In the prior art devices it has beennormal to use safety chains between the trailing and towing vehicles, tomaintain the alignment of the trailing vehicle with the towing vehicle,should the socket become disconnected from the ball. A considerableamount of slack is required in the chains to permit the normal swivelingaction of the trailer and this slack creates problems when the hitchbreaks or becomes disconnected and the only connection between thetrailer and the towing vehicle is the chains. The trailer is thenpermitted to whip from side to side due to the slack in the chains andmany wrecks have been traced to this whipping action which caused thedriver of the towing vehicle to lose control of the car.

SUMMARY OF THE INVENTION The present invention includes a yoke systemfor connecting the trailer tongue to the trailer hitch of the towingvehicle in addition to the normal ball and socket connectiontherebetween. The yoke is mounted so as not to restrain the normalrelationship between the trailer coupling and the trailer hitch on thetowing vehicle except when breakage or other disconnection therebetweenoccurs. In one form of the invention a finger is releasably positionedto overlie the trailer socket to prevent it from being disengaged fromthe ball.

The primary object of the invention is to provide a safety yokeconnection for maintaining the safe coupling of a trailer with itstowing vehicle in the event the normal coupling becomes broke ordisengaged.

Other objects and advantages will become apparent in the followingspecification when considered in light of the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of theinvention;

FIG. 2 is a side elevation of the invention;

FIG. 3 is a front elevation of the invention;

FIG. 4 is a longitudinally sectional view taken along the line 44 ofFIG. I looking in the direction of the arrows;

FIG. 5 is a transverse sectional view taken along the line 5- 5 of FIG.2 looking in the direction of the arrows;

FIG. 6 is a transverse sectional view taken along the line 6- 6 of FIG.2 looking in the direction of the arrows;

FIG. 7 is a view similar to FIG. 4 showing the release of the yoke fromthe trailer;

FIG. 8 is a top plan view of a modified form of the invention;

FIG. 9 is a longitudinally sectional view taken along the line 9-9 ofFIG. 8 looking in the direction of the arrows;

FIG. 10 is a horizontal sectional view taken along the line 10--10 ofFIG. 9 looking in the direction of the arrows;

FIG. 11 is a transverse sectional view taken along the line 1l11 of FIG.9 looking in the direction of the arrows;

FIG. 12 is a front elevation of the invention shown partially in sectionfor convenience of illustration;

FIG. 13 is a transverse sectional view taken along the line 1313 of FIG.9 looking in the direction of the arrows;

FIG. 14 is a view similar to FIG. 9 in reverse illustrating thedisconnection of the yoke from the hitch;

FIG. 15 is a detailed sectional view similar to FIG. 9 illustrating amodified form of the invention; and

FIG. 16 is a fragmentary perspective view of another modified form ofthe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings indetail wherein like reference characters indicate like parts throughoutthe several figures the reference numeral 20 indicates generally asafety trailer coupling constructed in accordance with the invention.

The coupling 20 includes a rigid hitch element 21 fomiing a part of orrigidly connected to a towing automobile (not shown) in a conventionalmanner. A tongue 22 extends forwardly from the trailing vehicle tocooperate with the hitch 21. A socket 23 is integrally secured to theforward end of the tongue 22 and has a hand wheel 24 associatedtherewith for clamping the socket 23 onto a ball 25 secured by a bolt 26to the hitch 21.

A connector generally indicated at 27 includes a generally rectangularbase plate 28 mounted on a bushing 29 carried by the bolt 26 above thehitch 21. The bushing 29 is slightly longer than the thickness of thebase plate 28 so that the base plate 28 is free to swivel thereabout. Awasher 30 is positioned in contact with the upper face of the base plate28 and the ball 25 is positioned thereon. A generally rectangular sidewall 31 extends upwardly from the side edge of the base plate 28perpendicularly thereto. A second side wall 32 extends upwardly from theopposite side of the base plate 28 parallel to the side wall 31. Theside walls 31, 32 are spaced apart sufficient to receive the socket 23therebetween as can be clearly seen in FIGS. 3 and 5. An invertedgenerally T-shaped slot 33 is formed centrally of the upper edge of "theside wall 31 and an identical generally T-shaped slot 34 is formedcentrally of the upper edge of the side wall 32. The lower edge of theT-shaped slots 33, 34 are formed convexly arcuate at 35 for reasons tobe assigned.

A yoke socket generally indicated at 36 includes a base member 37rigidly secured to the tongue 22 and a cap member 38 is pivotallysecured thereto by a pivot pin 39 extending transversely of the tongue22. The cap member 38 and the base member 37 in closed position have acentral bore 40 to receive a cylindrical portion 41 of the safety yokegenerally indicated at 42. An annular groove 43 is formed in the socketmember 36 communicating with the bore 40 to receive an annular shoulder44 formed on the cylindrical portion 41 of the yoke 42. A pair of bolts45 extend through the cap member 38 into the base member 37 to lock thesocket member 36 onto the yoke 42. The fit of the cylindrical portion 41in the bore 40 and the fit of the shoulder 44 in the groove 43 is suchthat with the socket 36 bolted closed by the bolts 45 the yoke is freeto rotate about its longitudinal axis.

The yoke 42 includes a pair of longitudinally extending arms 46, 47 andarranged in parallel relation spaced apart a distance slightly greaterthan the distance between the outside of the side walls 31, 32 as can beseen in FIG. 3. The arm 46 has a pin 48 which extends horizontallyinwardly to engage in the T-shaped slot 33. The arm 47 has a pin 49extending horizontally inwardly thereof and axially aligned with the pin48. The pin 49 engages in the T-shaped slot 34 with the yoke 42 inoperating position.

In the use and operation of the invention illustrated in FIG. 1 through7 the socket 23 is positioned in the ball 25 and the hand wheel 24 istightened to clamp the socket 23 thereon. The yoke 42 simultaneouslyengages the pins 48, 49 thereof in the T shaped slots 33, 34 and thetowing vehicle is fully connected to the trailer for operation. Theconnector 27 is adapted to swivel about the vertical axis bushing 29 asthe socket 23 swivels about the ball 25 during turning movements of thetowing vehicle. In the event that disconnection of the socket 23 fromthe ball 25 occur the pins 48, 49 engage within the front or rearportions of the T shaped slots 33, 34 to maintain the connection betweenthe trailer and the towing vehicle. Obviously the T-shaped slots 33, 34will retain the pins 48, 49 therein when the trailing vehicle is beingpulled by the towing vehicle or when the trailing vehicle is beingslowed by the towing vehicle. Swiveling movement of the yoke 42 withrespect to the tongue 22 is permitted by the socket 36 so that in thesituation where the trailing vehicle transversely tilts with respect tothe towing vehicle no strain is placed on the safety coupler 20.

Referring now to FIG. 8 though 14 a modified form of the invention isillustrated wherein the reference numeral 60 indicates generally asafety coupler for connecting a trailing vehicle to a towing vehicle. Asafety coupler 60 includes a rigid hitch element 61 which is connectedto or forms a part of the towing vehicle and a tongue 62 which extendsforwardly of a trailing vehicle (not shown).

A socket 63 is rigidly mounted on the forward end of the tongue 62 andhas a hand wheel 64 associated therewith for clamping the socket 63 on aball 65 connected by a bolt 66 to the hitch member 61.

A housing generally indicated at 67 includes a bottom wall 68 having acone shaped opening 69 extending therethrough. A cone shaped washer 70engages about the bolt 66 and against the hitch 61 centrally of the coneshaped opening 69 so as to retain the bottom wall 68 in its position onthe hitch 61 with enough slack allowed to permit the housing 67 toswivel about the washer 70 freely.

The housing 67 includes an upright side wall 71 on one side of the base68 and a second upright side wall 72 on the opposite side of the base68. An upright generally U shaped front wall 73 connects the side wall71, 72 completing the lower portion of the housing 67. The side wall 71has an L-shaped slot 74 opening downwardly therein from the uppersurface thereof and the side wall 72 has an L-shaped slot 75 openingdownwardly therein from the upper surface thereof.

A yoke support generally indicated at 76 is rigidly secured to thetongue 62 and includes a transverse slot 77 having a V- shaped top wall78. A yoke generally indicated at 79 is mounted through the slot 77 andincludes an arm 80 extending forwardly from one side thereof and asimilar arm 81 extending forwardly from the opposite side thereof. Thearm 80 has an offset portion 82 extending inwardly therefrom and havinga head 83 on its inner terminal end. The arm 81 has an offset endportion 84 extending inwardly thereon and having a head 85 on the innerend thereof. The offset portions 82, 84 and the heads 83, 85 arearranged in transversely aligned relation with the offset portions 82,84 being adapted to engage in the L- shaped slots 74, 75 respectivelywith the heads 83, 85 preventing the offset portions 82, 84 fromdisengaging laterally from the slots 74, 75 respectively.

A cover generally indicated at 86 is hingedly connected to the housing67 by a hinge pin 87. The cover 86 has a tongue 87 on one side thereofpositioned to engage in the slot 74 with the cover 86 in closedposition. A second tongue 88 is formed on the opposite side of the cover86 to engage in the slot 75 with the cover closed.

The side wall 71 has an L-shaped slot 89 formed therein rearwardly ofthe L-shaped slot 74. The side wall 72 has an L- shaped slot 90 formedtherein rearwardly of the L-shaped slot 75.

A latch bar 91 is pivotally mounted in the cover 86 on transverse pivotpins 92 and a coil spring 93 extends between the latch bar 91 and a boss94 on the cover 86. The latch bar 91 is normally urged rearwardly in thecover 86. A depending arm 95 is integrally formed on one end of thelatch bar 91 and a depending arm 96 is integrally formed on the otherend of the latch bar 91. A latch pin 97 is carried by the lower end ofthe arm 95 and a latch pin 98 is carried by the lower end of the arm 96for engagement respectively in the L-shaped slots 89, 90 to thus lockthe cover 86 in its closed position with the tongues 87, 88 respectivelyretaining the offset portions 82, 84 in their lower positions within theslots 74, 75 respectively.

In the use and operation of the invention the socket 63 is clamped tothe ball 65 in a conventional manner and the yoke 79 is dropped into theslot 74, 75 and the cover 86 is then closed and latched. The yoke 79 canswivel around a longitudinal axis due to the height of the slot 77 andthe V-shaped upper wall 78 thereof. To prevent the safety coupler 60from being placed under strain when the trailer tilts around itslongitudinal axis with respect to the towing vehicle. As the towingvehicle turns a comer the housing 67 swivels about the washer 70 topermit the yoke to stay in aligned relation with respect to the slots74, 75. In the event that the socket 63 should become disengaged fromthe ball 65 the yoke 79 will retain the connection between the towingvehicle and the trailing vehicle.

In the modification illustrated in FIG. 15 the housing 67 is identicalto the housing 67 except that the conical bore 69' is somewhat larger toaccommodate a conical washer 70' having a somewhat larger diameter. Anannular flange F on the washer 70' over the bottom wall 68 of thehousing 67 The bolt 66 of the ball 67. The bolt 66' of the ball 65' issomewhat larger in diameter than the bolt 66 and the changes in thebottom wall 68, washer 70 and the conical bore 69' permit the use of thelarger bolt 66. It should be noted that the housing 67 is permitted toswivel about the washer 70' in the same manner as the housing 67. In allother respects the modification illustrated in FIG. 15 is identical tothat of the form of the invention illustrated in FIGS. 8 though 14.

In FIG. 16 another modified form of the invention is illustrated whereina safety coupler is indicated generally at 100. The safety coupler 100includes a rigid hitch element 101 secured to or forming a part of thetowing vehicle and a tongue 102 extending forwardly from a trailingvehicle. A socket member 103 is secured to the forward end of the tongue102 and has a hand wheel 104 for clamping the socket member 103 to aball which is secured to the hitch 101 by a bolt 106. The constructionof the hitch member 101, tongue 102, socket 103, hand wheel 104, ball105 and bolt 106 are all of conventional construction and operate in theconventional manner.

A base member 107 is welded to the hitch 101 forwardly of the ball 105and has an upstanding bolt 108 secured thereto. A spacer 109 is mountedon the pipe 107 around the bolt 108 and a retainer 110 is mounted on thebolt 108 in contact with a spacer 109 for rotation thereon. A wing nut 1l l is mounted on the bolt 108 to engage the retainer 110 againstrotation on the bolt 108. A finger 112 is integrally formed with theretainer 110 and is adapted to be positioned over the socket 103 toprevent the socket 103 from becoming disengaged from the ball 105 shouldthe normal clamp actuated with the hand wheel 104 become broken orloosened. The retainer 1 10 can be swiveled to a position to permitdisengagement of the socket 103 from the ball 105 when the wing nut 11 1is loosened.

Having thus described the preferred embodiments of the invention itshould be understood that numerous other modifications and adaptationsmay be resulted to without departing from the spirit of the invention.

What is claimed is:

l. A trailer safety coupler of the type which includes a ball rigidlysecured to a hitch to a towing vehicle and a socket rigidly secured to atongue on the trailing vehicle and adapted for releasable pivotalconnection to the ball comprising a yoke having a pair of spaced apartarms secured to said tongue for pivotal movement about a longitudinalaxis, a connector housing secured to said hitch for pivotal movementabout the vertical axis of said ball, means on the ends of said yokearms cooperating with means on said connector housing for releasablysecuring said yoke to said housing for pivotal movement about atransverse axis extending through the center of said ball.

2. A device as claimed in claim 1, wherein the means on said connectorfor releasably securing said yoke to said hitch includes a pair of slotsformed in opposite sides of said housing with the means on said yokearms extending into said slots for securing said yoke to said housing.

3. A device as claimed in claim 1, wherein said yoke is releasablysecured to said tongue.

4. A device as claimed in claim 1, wherein said yoke is secured to saidtongue for pivotal movement about a longitudinal and about a transverseaxis.

5. A device as claimed in claim 1, wherein means are provided on saidyoke retaining means for releasably locking said yoke therein.

1. A trailer safety coupler of the type which includes a ball rigidlysecured to a hitch to a towing vehicle and a socket rigidly secured to atongue on the trailing vehicle and adapted for releasable pivotalconnection to the ball comprising a yoke having a pair of spaced apartarms secured to said tongue for pivotal movement about a longitudinalaxis, a connector housing secured to said hitch for pivotal movementabout the vertical axis of said ball, means on the ends of said yokearms cooperating with means on said connector housing for releasablysecuring said yoke to said housing for pivotal movement about atransverse axis extending through the center of said ball.
 2. A deviceas claimed in claim 1, wherein the means on said connector forreleasably securing said yoke to said hitch includes a pair of slotsformed in opposite sides of said housing with the means on said yokearms extending into said slots for securing said yoke to said housing.3. A device as claimed in claim 1, wherein said yoke is releasablysecured to said tongue.
 4. A device as claimed in claim 1, wherein saidyoke is secured to said tongue for pivotal movement about a longitudinaland about a transverse axis.
 5. A device as claimed in claim 1, whereinmeans are provided on said yoke retaining means for releasably lockingsaid yoke therein.